A uniform,solid,cylindrical flywheel of radius 1.4 m and mass 15 kg rotates at $2.7 \mathrm { rad } / \mathrm { s }$ What is the magnitude of the flywheel's angular momentum? A)40 kg ∙ m²/s B)20 kg ∙ m²/s C)80 kg ∙ m²/s D)60 kg ∙ m²/s

Question

Quizplus · Accepted Answer

The angular momentum $L$ of a solid cylindrical flywheel is given by $L = I\omega$, where $I$ is the moment of inertia of the cylinder and $\omega$ is the angular velocity. For a solid cylinder, $I = \frac{1}{2}MR^2$, where $M$ is the mass and $R$ is the radius. Substituting the given values, $I = \frac{1}{2} \times 15 \times (1.4)^2 = 14.7 \, \text{kg} \cdot \text{m}^2$, and $L = 14.7 \times 2.7 = 39.69 \, \text{kg} \cdot \text{m}^2/\text{s}$, which rounds to 40 kg·m^2/s.

A Uniform,solid,cylindrical Flywheel of Radius 1 2.7rad/s2.7 \mathrm { rad } / \mathrm { s }2.7rad/s

A Uniform,solid,cylindrical Flywheel of Radius 1 $2.7 \mathrm { rad } / \mathrm { s }$